Physical inactivity remains one of the leading global risk factors for morbidity and premature mortality. Despite extensive scientific evidence confirming the multidimensional health benefits of regular physical activity (PA), the proportion of individuals meeting recommended levels of physical activity remains low across all age groups. This article presents a narrative review of the literature, synthesizing the findings of key systematic reviews and international health promotion strategies in order to assess the effectiveness of various physical activity interventions from early childhood to older adulthood. The analysis highlights the significant role of behavioral, environmental, political, and psychosocial factors that substantially influence physical activity levels within populations. It also indicates that effective health promotion requires a multidimensional approach and collaboration across different sectors of social life. Integrating physical activity initiatives with education, proper nutrition, technological development, and local community engagement appears to be one of the most important directions for action, fostering greater regularity, accessibility, and equity in physical activity participation among diverse social groups.